On Mon, Jun 28, 2021 at 07:24:28PM -0700, Yonghong Song wrote: > > > > > While talking to Martin about the api he pointed out that > > callback_fn in timer_start() doesn't achieve the full use case > > of replacing a prog. So in the next spin I'll split it into > > bpf_timer_set_callback(timer, callback_fn); > > bpf_timer_start(timer, nsec); > > This way callback and prog can be replaced without resetting > > timer expiry which could be useful. > > I took a brief look for patch 4-6 and it looks okay. But since > you will change helper signatures I will hold and check next > revision instead. Thanks. The verifier patches won't change though. > > BTW, does this mean the following scenario will be supported? > prog1: bpf_timer_set_callback(time, callback_fn) > prog2: bpf_timer_start(timer, nsec) > so here prog2 can start the timer which call prog1's callback_fn? right. > > > > Also Daniel and Andrii reminded that cpu pinning would be next > > feature request. The api extensibility allows to add it in the future. > > I'm going to delay implementing it until bpf_smp_call_single() > > implications are understood. > > Do we need to any a 'flags' parameter for bpf_timer_start() helper > so we can encode target cpu in 'flags'? I thought that bpf_timer_init will handle the cpu selection, but you're right that having cpu in bpf_timer_start is more flexible. So I'll add a flag.
